Patent attributes
In one aspect, authentication information is received from a first processing device in a second processing device, and a digital signature is generated in the second processing device by signing data that incorporates at least a portion of the received authentication information. The received authentication information is generated at least in part from a secret seed stored in the first processing device. The received authentication information may be combined with the digital signature generated by the second processing device to form a joint signature that is transmitted to an authentication server. In an illustrative embodiment, the received authentication information comprises a tokencode and the digital signature is generated by signing data that incorporates the tokencode. The data that is signed to generate the digital signature may comprise an electronic document having the tokencode appended thereto.